The application relates generally to cooling electronic components. The application relates more specifically to cooling systems for variable speed drives and inductors.
A variable speed drive (VSD) for heating, ventilation, air-conditioning and refrigeration (HVAC&R) applications can include a rectifier or converter, a DC link and an inverter. Variable speed drives with current source inverter technology often utilize liquid cooled inductors. Medium voltage variable speed drives may also utilize liquid cooled inductors.
When a liquid cooled coil inductor is used, the coil conductors can be copper tubes that have been compressed to an oval shape. Coolant is circulated directly through the inductor tubing, requiring the use of de-ionized water to avoid plating out the copper into the cooling medium. A de-ionized cooling loop allows for good electrical insulation between the various electric components requiring cooling as the coolant is in contact with the inductor tubing as well as various other components that are a part of the cooling system.
In addition to the issues discussed above relating to VSDs and inductors, in the past, power assembly designs were bulky and heavy. They utilized aluminum electrolytic capacitors which have an inherent wear-out mechanism associated with the use of a liquid electrolyte and a seal. The aluminum electrolytic capacitors are physically heavy and are difficult to mount due to their cylindrical shape. The heatsinks were composed of either copper or aluminum material. Aluminum raises corrosion concerns when used in a closed loop uninhibited cooling system where copper components are also in contact with the cooling fluid. Even when inhibited fluid is used, it has a known lifetime and requires periodic and regular maintenance. Due to their significant weight, these power assembly designs have shown weaknesses in the area of wirebond failure within the insulated gate bipolar transistor (IGBT) module as a result of vibration. This weakness is also prevalent as a result of power/thermal cycling due to the variation in temperature between the heatsink, which mounts the IGBT module, and the laminated busbar, which electrically connects the IGBT modules together. The power assembly typically requires a metallic frame into which capacitors are inserted. IGBT power modules are typically mounted onto a heatsink and the heatsink is typically attached to the metal frame. Finally, a laminated busbar assembly is often placed on the top of the assembly and screws and clamps are used to hold the assembly together as a subassembly, which added to the bulk and weight of the designs.
Intended advantages of the disclosed systems and/or methods satisfy one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.